Re: Memory resident tree

Chiara,

 >How should I avoid this error?
Which error ?

To force a memory-resident Tree, do
 fTree = new TTree("TOFCalib","Tree for TOF Calibration");  fTree->SetDirectory(0);

Rene Brun

Chiara Zampolli wrote:
> Dear rooters,
>
> I have a problem with a method of a class where I have to build a
> tree starting from some other trees saved in files (the final tree is
> created with CopyEntries inside a loop). In particular, the problem
> lies on the fact that I first create the final tree, and the open the
> files where the others are in read mode. Here you can find the code:
>
> void AliTOFcalib::CreateTreeFromGrid(Int_t minrun, Int_t maxrun){
>
> // creating the chain with the trees for calibration
> // collecting them from reference data
> // from minrun to maxrun
>
> Float_t p[CHENTRIESSMALL];
> Int_t nentries;
> fTree = new TTree("TOFCalib","Tree for TOF Calibration");
> fTree->Branch("nentries",&nentries,"nentries/I");
> fTree->Branch("TOFentries",p,"TOFentries[nentries]/F");
> AliInfo("connected to alien");
> TGrid::Connect("alien://");
>
> Char_t filename[100];
> for (Int_t irun = minrun;irun<=maxrun;irun++){
>
> sprintf(filename,"alien:///alice/cern.ch/user/c/czampolli/TOFCalibReference_%i.root",irun);
>
> TFile *filegrid = TFile::Open(filename,"READ");
> TTree *tree = (TTree*)filegrid->Get("T");
> tree->SetBranchAddress("nentries",&nentries);
> tree->SetBranchAddress("TOFentries",p);
> fTree->CopyEntries(tree);
> delete tree;
> fNruns++; }
>
> The fTree, as you can see, is a private member of the class. Moreover,
> I don't need to write fTree on a file, for this reason I create it
> without opening any file.
> How should I avoid this error?
> Thank you a lot in advance.
> Best Regards,
> Chiara
> AliInfo(Form("Number of runs being analyzed %i",fNruns));
> }
>
Received on Fri Sep 28 2007 - 10:40:31 CEST